/*
 * Copyright 2002-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.util.xml;

import java.util.Map;
import javax.xml.XMLConstants;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;

import org.springframework.util.Assert;

/**
 * SAX {@link org.xml.sax.ContentHandler} and {@link LexicalHandler}
 * that writes to an {@link XMLStreamWriter}.
 *
 * @author Arjen Poutsma
 * @since 4.0.3
 */
class StaxStreamHandler extends AbstractStaxHandler {

    private final XMLStreamWriter streamWriter;


    public StaxStreamHandler(XMLStreamWriter streamWriter) {
        Assert.notNull(streamWriter, "XMLStreamWriter must not be null");
        this.streamWriter = streamWriter;
    }


    @Override
    protected void startDocumentInternal() throws XMLStreamException {
        this.streamWriter.writeStartDocument();
    }

    @Override
    protected void endDocumentInternal() throws XMLStreamException {
        this.streamWriter.writeEndDocument();
    }

    @Override
    protected void startElementInternal(QName name, Attributes attributes,
                                        Map<String, String> namespaceMapping) throws XMLStreamException {

        this.streamWriter.writeStartElement(name.getPrefix(), name.getLocalPart(), name.getNamespaceURI());

        for (Map.Entry<String, String> entry : namespaceMapping.entrySet()) {
            String prefix = entry.getKey();
            String namespaceUri = entry.getValue();
            this.streamWriter.writeNamespace(prefix, namespaceUri);
            if (XMLConstants.DEFAULT_NS_PREFIX.equals(prefix)) {
                this.streamWriter.setDefaultNamespace(namespaceUri);
            } else {
                this.streamWriter.setPrefix(prefix, namespaceUri);
            }
        }
        for (int i = 0; i < attributes.getLength(); i++) {
            QName attrName = toQName(attributes.getURI(i), attributes.getQName(i));
            if (!isNamespaceDeclaration(attrName)) {
                this.streamWriter.writeAttribute(attrName.getPrefix(), attrName.getNamespaceURI(),
                        attrName.getLocalPart(), attributes.getValue(i));
            }
        }
    }

    @Override
    protected void endElementInternal(QName name, Map<String, String> namespaceMapping) throws XMLStreamException {
        this.streamWriter.writeEndElement();
    }

    @Override
    protected void charactersInternal(String data) throws XMLStreamException {
        this.streamWriter.writeCharacters(data);
    }

    @Override
    protected void cDataInternal(String data) throws XMLStreamException {
        this.streamWriter.writeCData(data);
    }

    @Override
    protected void ignorableWhitespaceInternal(String data) throws XMLStreamException {
        this.streamWriter.writeCharacters(data);
    }

    @Override
    protected void processingInstructionInternal(String target, String data) throws XMLStreamException {
        this.streamWriter.writeProcessingInstruction(target, data);
    }

    @Override
    protected void dtdInternal(String dtd) throws XMLStreamException {
        this.streamWriter.writeDTD(dtd);
    }

    @Override
    protected void commentInternal(String comment) throws XMLStreamException {
        this.streamWriter.writeComment(comment);
    }

    // Ignored

    @Override
    public void setDocumentLocator(Locator locator) {
    }

    @Override
    public void startEntity(String name) throws SAXException {
    }

    @Override
    public void endEntity(String name) throws SAXException {
    }

    @Override
    protected void skippedEntityInternal(String name) throws XMLStreamException {
    }

}
